Deicing means for propellers



New. 25, 1952 L. H. ENOS 2,619,305

DEICING MEANS FOR PROPELLERS Original Filed Dec. 9, 1939 2 SHEETS SHEET l INVENTOR.

.LOUIS EENOS ATTOR EY NW 25, 1952 H. ENOS 2,619,305

DEICING MEANS FOR PROPELLERS INVENTOR. LOUIS Ii EH05 BY R A TTORNEY\ Patented Nov. 25, 1952 DEICING MEANS FOR. PROPELLERS Louis H. Enos, Montclair, N. J., assignor to Ourtiss-Wright Corporation, a corporation of Delaware Original applicationDecember 9, 1939, Serial No.

308,454. Divided and this application December 14, 1945, Serial No. 634,986

2 Claims.

This is a continuation of now abandoned application Serial No. 360,217, filed October 8, 1940. Application Serial No. 360,217 was a division of application Serial No. 308,454, filed December 9. 1939, which issued a Patent No. 2,335,018 on November 23, 1943.

This invention concerns aeronautical propellers, and in particular provides means for preventing the formation of ice on the blades of propellers whose pitch is either not adjustable or adjustable during operation.

It is known that the problem of ice formation on a propeller blade has been considered heretofore, and solutions of the problems have contemplated issuing de-icing fluid from a nozzle on the hub for spraying outwardly along the blade leading edge. Much of the fluid is thus Wasted. It is an object of this invention to provide de-icing means for the blades of propellers, controllable or otherwise, the invention providing for the feeding of de-icing fluid from stationary parts of the system to the rotating propeller in such manner that the fluid is fed and conducted for issuance along the leading edge of each blade. A further object is to provide a particular conduit construction for hollow propeller blades by which de-icing fluid is conducted to the leading edges of propeller blades. Still a further object is to provide means for feeding de-icing fluid to the leading edge of a cuff or fairing which embraces the root portions of a propeller blade.

Further objects will be apparent from a reading of the sub-joined specification and claims, together with an examination of the accompanying drawings, in which:

Fig. l is a side elevation of a controllable pitch aeronautical propeller mounted upon the nose of an engine, the propeller incorporating the provisions of the invention;

Fig. 2 i a section through a blade of the propeller on the line 2--2 of Fig. 3;

Fig. 3 is a longitudinal section through one of the propeller blades;

Fig. 4 is an enlarged section on the line 4-4 of Fig. 1;

Fig. 5 is a fragmentary elevation of a mounted propeller blade showing a fairing cuff in section; and

Fig. 6 is an enlarged section on the line 6-6 of Fig. 5.

Referring to Fig. 1, a propeller hub Ill carrying a power unit I I and a speed reducer 12 at its forward end, is drivably mounted upon a shaft extending from an engine nose IS, the elements ll 2 and I2 serving to selectively increase or decrease the pitch of the propeller blades, one of which is shown at M, in a manner well known in the art. The blades ar rotatably mounted in the hub on thrust bearings, also known to the art, and the particular type of blade shown comprises a hollow shell of steel or other suitable material, having a cross-section as indicated in Fig. 2. The root or shank portion of the blade, shown at [5 in Fig. 3, is cylindrical in form and is provided with an integral flange Hi the butt of the blade being interiorly threaded as at I! to receive a screw abutment which cooperates with the hub bearing assembly. Within the hollow of the blade Id, at its leading edge, a small tube I9 is secured as by brazing, the brazing fillet being indicated at 20. At spaced apart interval along the blade leading edge small holes or passageways 2| are formed, these being drilled through the leading edge of the blade and through one wall of the tube l9 to allow of the issue of fluid fed to the tube H) at the blade butt to the outside of the blade surface for the purpose of dissolving ice which may form thereon during operation. A suitable fluid might comprise alcohol, glycerine or the like.

In order to feed de-icing fluid to the blade, an inlet drilling 22 is formed through the blade butt radially inward of the flange l6, and a fitting 23 is secured around the blade butt comprising elements 24 and 25 hinged at 26 and secured to the blade by a clamp bolt 21. The element 24 is provided with a segmental passage or conduit 28 communicating at one end with the drilling 22 and at its other end with a drilling 30 opening to an inwardly facing segmental trough 3! formed in a segmental boss 32 integral with the element 24. The segmental trough 3| is concentric with the butt portion of the blade and has an arc of embracement substantially equal to the angular pitch change in the blade which may be expected during operation. To the propeller hub and rotatable therewith is secured an annulu 34 having a catch slot 35 and provided with radially extending nozzles 36, each of which lies opposite one of the troughs 3|. Secured to the engine nose is a pipe line 38 through which de-icing fluid is fed from a suitable reservoir, this tube terminating in a nozzle 39 directed into the catch slot 35.

In operation, when fluid is fed through the tube 38 it is delivered to the catch slot 35 whence it passes through the nozzles 36 into the grooves 3| of the propeller blades. Since the annulus 34 is rotating rapidly with the propeller hub, the de-icing fluid is thrown by centrifugal force through the nozzles 36 and into the grooves 3| whence it passes through the conduits described to the leading edge of the propeller blade.

In some types of propellers, the blades tend toward a circular cross-section at their root ends, and to endow them with greater aerodynamic efiiciency, a sheet metal cuff or fairing may be clamped to the blades. Such a cufi is shown in Figs. 5 and 6 at 40. These cuffs extend possibly one-quarter of the blade length from the hub, and on propellers equipped with the cuifs effective de-icing may be attained by fitting a de-icing fluid conduit to the leading edge of the cuff 40 whence de-icing fluid sprays substantially radially outward along the balance of the propeller blade to prevent the formation of ice thereon. In applying the invention to propeller cufis, the conventional forging 4| which forms the base for the cuff replaces the assembly 23 above described and carries a segmental portion 32 having a segmental trough 3| for reception of deicing fluid. A passage 28 in the forging 4| conducts de-icing fluid toward the leading edge of the cuff whence it issues to a tube 42 brazed to the inside of the leading edge portion of the cuff. Drlllings 43 through the cuff and one wall of the tube permit the flow of fluid to the leading edge of the cuff for de-icing purposes. The cufi, incidentally, is rigidly secured to th forging 4| which may be passed over the cylindrical butt end of the propeller blade before assembly of the blade in the hub, the member 4| abutting upon the flange IE to constrain it against displacement 11116 to centrifugal force. The outer end of the cuif conforms in general to the profile of the propeller blade at that station, but is in clearance relation thereto, the clearance space being filled with a soft resilient material such as rubber or leather, such gasket being shown at 44. This gasket prevents abrasion of the polished surfaces of the propeller blade.

The tube 42 may be extended as at 45 through the outer cuiT edge to form a nozzle to spray deicing fluid along the leading edge of the blade 14 in addition to feeding fluid to the cuff leading edge. Although a sheet metal cuif has been shown, the invention is intended to cover de-icing provisions for cuffs and blades of any material.

The means for feeding the segmental trough 3| is the same as that shown in Fig. 1, comprising the annulus 34 having a catch slot 35 and nozzles 36, the catch slot being fed from a nozzle 4 39 at the end of the fluid conduit 38 secured to the engine.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications and changes.

I claim:

1. A hollow metallic propeller blade comprising components blending into one another to comprise a curved leading edge, a tube disposed within the hollow defined between the inner surfaces of the components, within the leading edge, and enlarged fused metal fillets between the tube and components to secure the tube to the components, said fused metal being so disposed as to augment the strength of the blade leading edge.

2. A hollow metallic propeller blade comprising components blending into one another to comprise a curved leading edge, a tube disposed within the hollow defined between the inner surfaces of the components, within the leading edge, enlarged fused metal fillets between the tube and components to secure the tube to the components, said fused metal being so disposed as to augment the strength of the blade leading edge and means to feed an anti-icing fluid to said tube, said leading edge and tube having at least one passageway formed therein for issue of the fluid to the exterior surface of the propeller blade.

- LOUIS H. ENOS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,899,689 Houston Feb. 28, 1933 2,007,776 Smith July 9, 1935 2,087,919 Mascuch et al July 27, 1937 2,091,395 Perrin Aug. 31, 1937 2,097,926 Kimball Nov. 2, 1937 2,334,175 Clay Nov. 16, 1943 2,335,018 Morris et a1 Nov. 23, 1943 FOREIGN PATENTS Number Country Date 837,466 France Nov. 12, 1938 

